1. Field of the Invention
The present invention relates to an image forming apparatus, an image forming method, and a computer-readable recording medium.
2. Description of the Related Art
Known printing apparatuses perform printing based on image information about an image to be printed and information that indicates, for example, paper used for the printing. In this process, it is first detected whether paper is loaded in a paper feeding unit. An image forming process is started based on the image information only after it is detected that paper is loaded in the paper feeding unit.
If the image forming process involves use of a plurality of developing units, however, the image forming process requires a longer time than time required by a paper feeding process, so that the paper feeding process is started after the image forming process is started (see Japanese Patent Application Laid-open No. 2010-211119, for example). In the technique disclosed in Japanese Patent Application Laid-open No. 2010-211119, unlike the known printing apparatuses, the image forming process is started without any confirmation that paper is loaded.
Another known technique allows a job, among others in a standby state, not affected by an error to be processed without suspension when a paper-out condition or other error occurs in a printing apparatus (see Japanese Patent Application Laid-open No. 2000-062292, for example). In the technique disclosed in Japanese Patent Application Laid-open No. 2000-062292, when one paper feed tray is not replenished with additional paper, a job that is set to use another paper feed tray loaded with paper is preferentially subjected to printing.
In the image forming apparatus that uses a technique as described above, however, an image forming process for a first job is started and then an image forming process for a second job is started before a paper feeding process for the first job is started. If the paper feeding unit, for example, no paper is loaded in a paper feed tray at a point in time at which the paper feeding process is started, therefore, the image forming process in accordance with the second job that follows the first job is already started before that particular point in time. Assume that the recording medium associated with the second job is available at this time, the image forming process for the first job is suspended, while the image forming process for the second job is continued. This results in the following: specifically, whereas an incomplete set of recording media with the image formed thereon in accordance with the first job is discharged to a discharging unit, for example, a discharge tray, a complete set of recording media with the image formed thereon in accordance with the second job is discharged. Therefore, a user has an incomplete set of recording media with the image formed thereon in accordance with the first job mixed with a complete set of recording media with the image formed thereon in accordance with the second job on the discharging unit, for example, the discharge tray, so that the user is confused.